Re: [dpdk-dev] [PATCH V2] ethdev: add queue state when retrieve queue information

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

Hi,

> Currently, upper-layer application could get queue state only
> through pointers such as dev->data->tx_queue_state[queue_id],
> this is not the recommended way to access it. So this patch
> add get queue state when call rte_eth_rx_queue_info_get and
> rte_eth_tx_queue_info_get API.
> 
> Note: The hairpin queue is not supported with above
> rte_eth_*x_queue_info_get, so the queue state could be
> RTE_ETH_QUEUE_STATE_STARTED or RTE_ETH_QUEUE_STATE_STOPPED.

I wonder why RTE_ETH_QUEUE_STATE_HAIRPIN Is not supported?
Obviously what we do - copy internal queue state to the user provided buffer.

> Note: After add queue_state field, the 'struct rte_eth_rxq_info' size
> remains 128B, and the 'struct rte_eth_txq_info' size remains 64B, so
> it could be ABI compatible.
> 
> Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
> Signed-off-by: Lijun Ou <oulijun@huawei.com>
> ---
> V1->V2:
> - move queue state defines to public file
> ---
>  doc/guides/rel_notes/release_21_05.rst |  6 ++++++
>  lib/librte_ethdev/ethdev_driver.h      |  7 -------
>  lib/librte_ethdev/rte_ethdev.c         |  3 +++
>  lib/librte_ethdev/rte_ethdev.h         | 11 +++++++++++
>  4 files changed, 20 insertions(+), 7 deletions(-)
> 
> diff --git a/doc/guides/rel_notes/release_21_05.rst b/doc/guides/rel_notes/release_21_05.rst
> index 22aa80a..503daf9 100644
> --- a/doc/guides/rel_notes/release_21_05.rst
> +++ b/doc/guides/rel_notes/release_21_05.rst
> @@ -164,6 +164,12 @@ ABI Changes
> 
>  * No ABI change that would break compatibility with 20.11.
> 
> +* Added new field ``queue_state`` to ``rte_eth_rxq_info`` structure
> +  to provide indicated rxq queue state.
> +
> +* Added new field ``queue_state`` to ``rte_eth_txq_info`` structure
> +  to provide indicated txq queue state.
> +
> 
>  Known Issues
>  ------------
> diff --git a/lib/librte_ethdev/ethdev_driver.h b/lib/librte_ethdev/ethdev_driver.h
> index cdd4b43..ec5a17d 100644
> --- a/lib/librte_ethdev/ethdev_driver.h
> +++ b/lib/librte_ethdev/ethdev_driver.h
> @@ -970,13 +970,6 @@ struct eth_dev_ops {
>  };
> 
>  /**
> - * RX/TX queue states
> - */
> -#define RTE_ETH_QUEUE_STATE_STOPPED 0
> -#define RTE_ETH_QUEUE_STATE_STARTED 1
> -#define RTE_ETH_QUEUE_STATE_HAIRPIN 2
> -
> -/**
>   * @internal
>   * Check if the selected Rx queue is hairpin queue.
>   *
> diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
> index 3059aa5..fbd10b2 100644
> --- a/lib/librte_ethdev/rte_ethdev.c
> +++ b/lib/librte_ethdev/rte_ethdev.c
> @@ -5042,6 +5042,8 @@ rte_eth_rx_queue_info_get(uint16_t port_id, uint16_t queue_id,
> 
>  	memset(qinfo, 0, sizeof(*qinfo));
>  	dev->dev_ops->rxq_info_get(dev, queue_id, qinfo);
> +	qinfo->queue_state = dev->data->rx_queue_state[queue_id];
> +
>  	return 0;
>  }
> 
> @@ -5082,6 +5084,7 @@ rte_eth_tx_queue_info_get(uint16_t port_id, uint16_t queue_id,
> 
>  	memset(qinfo, 0, sizeof(*qinfo));
>  	dev->dev_ops->txq_info_get(dev, queue_id, qinfo);
> +	qinfo->queue_state = dev->data->tx_queue_state[queue_id];
> 
>  	return 0;
>  }
> diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h
> index efda313..4f0b1b2 100644
> --- a/lib/librte_ethdev/rte_ethdev.h
> +++ b/lib/librte_ethdev/rte_ethdev.h
> @@ -1582,6 +1582,13 @@ struct rte_eth_dev_info {
>  };
> 
>  /**
> + * RX/TX queue states
> + */
> +#define RTE_ETH_QUEUE_STATE_STOPPED 0
> +#define RTE_ETH_QUEUE_STATE_STARTED 1
> +#define RTE_ETH_QUEUE_STATE_HAIRPIN 2
> +
> +/**
>   * Ethernet device RX queue information structure.
>   * Used to retrieve information about configured queue.
>   */
> @@ -1591,6 +1598,8 @@ struct rte_eth_rxq_info {
>  	uint8_t scattered_rx;       /**< scattered packets RX supported. */
>  	uint16_t nb_desc;           /**< configured number of RXDs. */
>  	uint16_t rx_buf_size;       /**< hardware receive buffer size. */
> +	/**< Queues state: STARTED(1) / STOPPED(0). */

I think comment has to state that possible values are one of
RTE_ETH_QUEUE_STATE_*.
About previous discussion about new field in this struct vs new API function,
I still think new function will be a bit cleaner, but could live with both.

> +	uint8_t queue_state;

If we'll go with new 1B field, then as Stephen pointed,
it is probably worth to fill the hole between scattered_rx
and nb_desc with this new filed.

>  } __rte_cache_min_aligned;
> 
>  /**
> @@ -1600,6 +1609,8 @@ struct rte_eth_rxq_info {
>  struct rte_eth_txq_info {
>  	struct rte_eth_txconf conf; /**< queue config parameters. */
>  	uint16_t nb_desc;           /**< configured number of TXDs. */
> +	/**< Queues state: STARTED(1) / STOPPED(0). */

Same about comment here.

> +	uint8_t queue_state;
>  } __rte_cache_min_aligned;
> 
>  /* Generic Burst mode flag definition, values can be ORed. */
> --
> 2.7.4